
public class Demo3 {

	public static void main(String[] args) {
		int a=20;
		int b=10;
		
		int index;
		
		index=a;//index=20,a=20,b=10
		a=b;//index=20,a=10,b=10	
		b=index;//index =20,b=20,a=10
		System.out.println(a+","+b);
	}

}
